The K22 applicant, Dr. Jacob Garza, obtained his Ph.D. in Pharmacology at the University of Texas Health Science Center at San Antonio (Supervisor: Dr. Xin-Yun Lu) supported by an F31 Individual Predoctoral NRSA fellowship. His thesis research focused on mechanisms underlying the antidepressant-like effects of the adipocyte-derived hormone leptin. He subsequently completed three years of postdoctoral training in neuroscience at the same institution studying neural stem cell regulation under the support of an NRSA T32 Institutional Research Training Grant. To diversify his research training, Dr. Garza accepted a new postdoctoral position in November 2013 in the Department of Psychiatry at the Massachusetts General Hospital (MGH) in the laboratory of his primary mentor on this application, Dr. Tracey Petryshen. This new position falls within his research interest in neurological and neuropsychiatric disorders, and expands his training to human psychiatric genetics and molecular neuroscience. Dr. Garza's immediate goals for this award are to obtain training in the following areas: 1) human genetics, 2) iPSC and human neural progenitor cell models, 3) genome editing technology and 4) clinical, neurobiological, and genetic aspects of autism spectrum disorder. In order to accomplish this, he has assembled a spectacular team of experts in each of the fields in which he will acquire training and gained support from world-class researchers. The mentoring committee is highly diverse and incorporates faculty members from a range of positions. The laboratories of the primary mentor (Dr. Tracey Petryshen) and the co-mentors (Dr. Mark Daly and Dr. Stephen Haggarty) are located within the MGH Center for Human Genetic Research (CHGR). These three investigators are also affiliated with the Stanley Center for Psychiatric Research at the Broad Institute of MIT and Harvard. These institutions are located in close proximity to Harvard University, Massachusetts Institute of Technology, Harvard Medical School and its teaching hospitals (of which the MGH is the flagship), and numerous other universities and research institutes. This incredibly rich scientific environment offers an outstanding training opportunity through interactions with leading researchers in autism research. Dr. Garza's long-term career goal is to establish himself as an independent investigator at an academic institution. He envisions maintaining a strong, well-funded research program focused at identifying mechanisms of neurological and neuropsychiatric disorders and would like to incorporate aspects of basic science and translational research. The environment at MGH is excellent for establishing collaborations between clinical and basic researchers and is extremely beneficial for Dr. Garza's long-term goals. The proposed research project focuses on autism spectrum disorder (ASD), a severe developmental neurological disorder that affects as many as 1 in 68 children. ASD is typically characterized by abnormal cognition, inhibition of social behaviors and onset of focused, isolated, or repetitive behaviors. While neuroanatomical studies have suggested abnormal brain connectivity and development of key structures involved in executive function, the underlying causes are not known. This lack of knowledge hinders the identification of new molecular targets for the development of effective treatments. Recent large-scale patient genomic studies have identified candidate genes that are highly associated with ASD, including the ankyrin-2 gene (ANK2), which has repeatedly been implicated by ASD exome sequencing studies. ANK2 encodes the ankyrin-B membrane associated scaffolding protein that plays an integral role in neuronal function, particularly axon guidance and growth, thus disruption to ankyrin-B may have critical consequences for brain function. This proposal will characterize the functional consequences of three loss-of-function mutations in ANK2 that were recently discovered in ASD patients. Aim 1 will utilize human neuronal model to study the mutation effects on neuronal development and morphology. Aim 2 will examine the impact of the most severe mutation on the function of neural circuits regulating behaviors that are abnormal in ASD. Both of these aims will be completed during the training phase of this award. During the independent phase of this award, Aim 3 will use the CRISPR/Cas9 system to generate mice with germline mutations in ANK2 that are present in ASD patients, and study the effects on brain development and ASD-like behaviors. The experiments utilized in this project will incorporate a wide array of research techniques including genomic engineering using the CRISPR/Cas9 system, adeno-associated viral vector delivery to the mouse brain, quantitative PCR, animal behavior analysis related to ASD, and development of a human neural progenitor cell model. The expected outcome of the research aims is dissection of the mechanisms of ANK2 in neural impairments underlying ASD, which is critical for improving our understanding of this disorder and developing effective interventions and treatments.